If you run a farrago script such as ant test in the background, it will hang when it gets to execution of installation scripts. When this happens, you have to put it back in the foreground to get it to proceed. This seems to have something to do with sqlline's Java terminal manipulation. To avoid this, execute the bash command set +m before starting the background job. Other shells may require a different command.
The command above disables job control, which may be undesirable. To restore the normal setting, execute set -m